Machine guard



J. DEMINSKI MACHINE GUARD Filed March 24, 1924 All:

pvvavrof? r L/(w/v Dawn 14 Val 2 37170 7 51.

alienated Mar. 31, 1325.

UNITED STATES ,531,851 PATENT cri cs;

JOHN DEMINSKI, or sir; LOUIS, MISSOURL.

MACHINE GUARD.

Application filed March 24:, 1924.

To all whom it may concern:

tion of a power sewing machine when the needle breaks, it is apt to be hurled in all direct-ions and may injure the operator. Furthermore, unless the operator exercises the highest degree of care at all times, his fingers may be caught under the needle causing severe injuries. My device is made of few and simple parts and can be easily affixed to the conventional sewing machine without materially altering the machine itself. My device lends itself readily to multiple production and. is entirely automatic in its action.

With these and other objects in view, my invention has relation to certain novel features of construction and arrangement of parts as will be hereinafter more fully described, pointed out in the claim and illustratcd in the drawings in which Fig. 1 is a front elevation of my device showing the guard in its inoperative position.

Fig. 2 is a plan view of Fig. 1 showing the guard in inoperative position in solid line and in operating position in dashed line.

Fig. 3 designates a cross section along the line 33 of Fig. 2 and Fig. 41 designates a cross section along the line 4-1 of Fig. 2.

A sewing machine is not shown except that a fragment of the head is shown schematically and a fragment of a bracket is likewise shown and the support for the lever on the machine that operates my device is likewise shown. A fragment of the needle is additionally shown.

Numeral 5 designates a fragment of the machine head to which one end of my device is secured by the lug end eye 6. Numeral 7 designates a fragment of a bracket secured to the machine frame to which the other end of my device is secured by means of the support 8. Numeral 9 designates a lever pivotally secured to the frame of the ma- Serial No. 701,296.

chine at 10. Numeral 11 designates the I fragment of the needle from which the operator is to be protected by the guard/element of my device. The lever 9is operated by the machine by mechanism not disclosed in the following manner: I

When the power is applied to themachi-ne so that the needle begins its reciprocating movement the lever 9 is rotated very slightly in a clockwise direction in Fig. i 1. This movement causes the guard 12 to be'rotated from the inoperative or non-guardingjposition shown in F 1g. 1 to the operative or guarding position shown in Fig. 2; When the machine is stopped the lever 9 is rotated in an anti-clockwise direction through "a" very small are about its fulcrum at 10, thereby becoming disengaged from my device.

My devlce comprises the rod 13 which is split intermediate its length and secured together by the link 14, which link is de tachably fastened to the ends of the rod 13 by means of the screws 15, passes through holes in the link 14 and holes in the ends of the rod 13. The purpose of this link is to adjust the length of therod '13 and for I that reason the holes in the link 14 are elongated so as to be slots. By loosening, the screws 15 they may be moved longitudinally in the slots. The one end of the rod 13 terminates in a rack 16 and the other end terminates in a finger 17. The cross section of the rod is of the same size as the hole 18' formed in the support 8 so that the rod 13 is in sliding engagement in the support 8. On to the lug and eye 6 is se- I cured the split housing 18 into which the rack end of the rod 13 passes through a hole in the end of the housing. The guard 12 is mounted on the trunnion 19, which trunnion passes through the side wall of the 7 split housing 18 into the split housing 18. On to the inner end of the trunnion 19 is secured the pinion 20. Numeral 21 designates a trunnion mounted in the split housthe teeth on the rack 16 so that when the rack 16 is moved longitudinally that the pinion 23 is rotated. It will, therefore, be seen that when the rod 13 is moved longitudinally that the guard 12 will beoscillated, i. e. rotated for a portion of a revolution. By making the gear ratio between the pinion 20 and 22 suiiiciently great, a slight movement of the rod 13 will cause the guard 12 to rotate through an arc of ninety degrees. I preferably make this gear ratio three to one, i. e. to say, that when the pinion 22 is rotated one-third of a revolution that the pinion 20 has made a complete revolution. Of course, the pinion 20 in my device will never make a complete revolution, i. e. to say, it will only make one-fourth of a revolution. Since the movement of the lever 9 is very small it will move the rod 13 only a very short distance. Practically it will move the rod 13 only three-eighths of an inch, but this movement will be sufficient to cause the guard 19 to move ninety degrees, i. e. to say, from a non-operative or non-guarding position to an operative or guarding position.

When the'machine is stopped the lever 9 will move three-eighths of an inch in an anti-clockwise direction, but it will not take the rod 13 with it so that it is necessary for me to provide means for returning the rod 13 to its original position, i. e. to the position that it is in'when the guard 12 is in a non-guardmg position. For the purpose of accomplishing this, I have provided the coil spring 24 which is secured to the rod 13 by means of one of the screws 15 and is secured to the stationary frame at 25 by hook and eye construction 26 as best shown in Figs. 1 and 2. The split housing 18 which is made of two parts may be held together by means of screws 27. The guard 12 has its external. end bent to the arc of a circle so that it will completely intercept any object from reaching the needle 11 when it is I in the guarding position.

The guard 12 may be secured to the trunnion 19 by means of a set screw 28.

In the operation of my device it is only necessary to start the machine that is to apply the power and the guard 12 will immediately move to the guarding position. When the power is shut off the guard will automatically oscillate to its non-guarding position.

What I claim and mean to secure by Letters Patent is A device of the character described comprising dual means for securing it to a ma chine, a rod in sliding engagement in one of said means, a split housing secured to the other of said means, said rod passes into said split housing and terminating in a rack, which rack is in mesh with a pinion secured in said split housing, which pinion is mounted on a trunnion on which is also mounted a second pinion, which pinion is in mesh with a third pinion mounted on a second trunnion secured in said split housing, a guard secured to the trunnion on which said third pinion is mounted.

In testimony whereof I affix my signature.

JOHN DEMINSKI. 

